How do you define diving at a site where the water only manages to exceed 6m depth when the peak of a big wave rolls over. A great big long decompression stop comes to mind, but this site is far too interesting to be a deco stop. Yesterday we returned again to this derelict pier looking to increase the nudibranch species count and we did.

As in other recent visits sea hares, sea lemons and grey sea slugs were numerous, in fact I think that I could stick my neck out and say locally abundant. The sea hares may be present in considerable numbers well beyond the pier, we found them on the adjacent rocks, sand and seaweed. Also under the pier are some juvenile and smaller nudibranch species which despite their bright colours are easily overlooked.  Each of the Facelina nudibranchs in the image above is about 1cm in length.

Some of the larger nudibranchs such as the sea lemon (Doris pseudoargus) use their colour and skin texture to emulate the sponges on which they feed allowing them to blend into the background. The nudibranch Geitodoris planata (formerly Discodoris planata) shown above also feeds on sponges and is big enough to see without a magnifying glass – that is if you don’t just swim past it. By combining its flat profile with a subdued colour pattern and disruptive texture it appears to be a static encrusting invertebrate. The deception is complete when the gill plume and horns are withdrawn into the body. Look carefully at the image above, both gills and horns are extended but the slug still looks like a lump of sponge.  

After just over an hour when frozen fingers had started to fumble the camera controls we gave up and left the water. Shortly afterwards a hot drink, winter sunshine and superb views across to the snow covered peaks on Arran delivered the “place to be ” ambience.